HTML 5 comes with a bunch of new tags that IE6 cries that it doesn’t know them, thus refusing to style them according to the CSS. To baby-sit this stupid browser one last time, adding these JavaScript lines in the <head> of your web page that utilizes HTML 5 tags:
<script>
document.createElement('header');
document.createElement('nav');
document.createElement('section');
document.createElement('article');
document.createElement('aside');
document.createElement('footer');
</script>
Will make IE6 *know* these tags and style them correctly by CSS.